Floating couplings are commonly employed in plunger type pumps to connect the plunger or drive shaft of the pump to a driven piston mounted for reciprocating motion in a cylinder coaxial with the drive shaft. A floating coupling is utilized to minimize the effects of eccentric and angular misalignment between the piston drive mechanism and the piston which upon motion of the piston produces undesired wearing of the seals around and supporting the piston with incident fluid leakage therefrom. In the past, such floating couplings have included one or more spring members between the piston and the piston drive mechanism to maintain an extension from the piston included in the coupling in constant contact with the piston drive mechanism. In practice, such springs restrict the freedom of the piston to orient itself upon the occurrence of eccentric or angular misalignment between the piston and the piston driving mechanism. In particular, such springs introduce forces opposing movement of the piston in directions perpendicular to the axis of the piston drive mechanism. Further, the axial forces provided by the spring members may be uneven. In such instances, the spring members: may introduce forces normal to the preferred motion of the piston and further enhance the undesired wear of the associated seals and hence the incidence of undesired fluid leakage.